Earth-working machines, such as cable shovels, excavators, wheel loaders, and front shovels, include implements generally used for digging into, ripping, or otherwise moving earthen material. These implements are subjected to extreme abrasion and impacts that causes them to wear. To prolong the useful life of the implements, various ground engaging tools can be connected to the earth-working implements at areas experiencing the most wear. These ground engaging tools are replaceably connected to the implements using a retention system.
An exemplary system for retaining a ground engaging tool connected to an implement is disclosed in U.S. Pat. No. 4,067,657 of Kaarlela that issued on Jan. 10, 1978 (“the '657 patent”). Specifically, the '657 patent discloses a cam lock retaining means for a ripper. The cam lock retaining means includes a cylindrical pin that passes through corresponding bores in a ripper shank and a ripper tip. Spaced apart keys are reciprocally mounted within an outer annular surface of the pin, and set screws are threadingly disposed within opposing axial ends of the pin. As torque is applied to the set screws, the set screws are driven axially into the pin to engage ends of the associated keys and urge them radially outward into bearing contact with the ripper tip, thereby securing the tip to the shank.
Although acceptable for some applications, the retaining means of the '657 patent may be less than optimal. In particular, over time, the components of the shank, tip, and retaining means can wear, resulting in loosening of the joint. Although additional tensioning of the set screws may re-tighten this engagement, eventually enough wear may occur such that additional tensioning is not possible. When this occurs, the retaining means must be replaced. This replacement can be time consuming and costly. In addition, loosening of the joint may give false impressions to a machine operator regarding durability of the retaining means. Further, because the keys of the '657 patent are separately extended to contact the ripper tip, it may be possible for the cylindrical pin to be cocked within a bore of the ripper shank. This could lead to premature loosening or damage of the joint.
The disclosed tool retention system is directed to overcoming one or more of the problems set forth above.